#include <iostream>

using namespace std;


namespace hello{
namespace ver1{
    void fun(){
        cout << "i am fun in ver1" << endl;
    }

    inline namespace ver2{
        void fun1(){
            cout << "i am fun in ver2" << endl;
        }
    }
}
inline namespace ver3{
    void fun(){
        cout << "i am fun in ver3" << endl;
    }
}

}


int main(){
    hello::ver1::fun();
    hello::fun();
}